It is known that the size, particularly the width of contact systems for the principal current of low voltage circuit breakers depends on a nominal current for which the low voltage circuit breakers have been designed. The higher this nominal current, the wider is the embodiment of the corresponding contact systems for a principal current. A disadvantage here is the fact that on the basis of strongly defined proximity effects for wider contact systems for a principal current, a complicated arc extinction behavior is exhibited because the arc predominantly occurs at the edge of the wide contact systems for a principal current and ac-cordingly predominantly dwells in the edge zone of the arc extinction chamber allocated to the contact systems for a principal current. As a result, the cooling effect of the arc extinction chamber is only used in a limited manner. This leads to the fact that the arc is extinguished rela-tively late and the danger arises that ionized circuits may escape from the arc extinction chamber. This burning off or down of the arcs in the edge zone occurs both during inter-ruptions in the nominal current zone and during short-circuit interruptions of this low voltage circuit breaker.
In order to make possible an explicit transmission of arcs into extinction chambers, it is known from DE 35 39 673 A1 that an arc-conductive piece of a ferromagnetic mate-rial must be allocated to a contact system for a principal current by means of which the arcs are to be explicitly transmitted to the arc extinction chamber. The disadvantage of this arrangement is the fact that additional components must be provided which are directly connected to the contact systems for a principal current. This complicates the struc-ture of the low voltage power switch and low manufacturing and/or assembly tolerances already lead to a failure when the arcs are conducted away.
In addition, it is known in the case of a low voltage circuit breaker according to said type that provision must be made for an arc guiding element on the arc transmitting element which makes it possible to direct said arc in a de-fined manner to the arc extinction chamber (US 6,417,474 B1).
Publication US 4,885,441 describes an arc transmitting element with an arc guiding element in which the arc guiding element has two running edges running at different angles to a center line of the arc transmitting element in which case the running edges extend away from an edge zone in the di-rection of a middle zone of the arc transmitting element.